Abstract
Assessment of the cumulative incidence of SARS-CoV-2 infections is critical for monitoring the course and extent of the COVID-19 epidemic. Here, we report estimated seroprevalence in the ...French population and the proportion of infected individuals who developed neutralising antibodies at three points throughout the first epidemic wave. Testing 11,000 residual specimens for anti-SARS-CoV-2 IgG and neutralising antibodies, we find nationwide seroprevalence of 0.41% (95% CI: 0.05–0.88) mid-March, 4.14% (95% CI: 3.31–4.99) mid-April and 4.93% (95% CI: 4.02–5.89) mid-May 2020. Approximately 70% of seropositive individuals have detectable neutralising antibodies. Infection fatality rate is 0.84% (95% CI: 0.70–1.03) and increases exponentially with age. These results confirm that the nationwide lockdown substantially curbed transmission and that the vast majority of the French population remained susceptible to SARS-CoV-2 in May 2020. Our study shows the progression of the first epidemic wave and provides a framework to inform the ongoing public health response as viral transmission continues globally.
Long-term exposure to air pollution (AP) has been shown to have an impact on mortality in numerous countries, but since 2005 no data exists for France.
We analyzed the association between long-term ...exposure to air pollution and mortality at the individual level in a large French cohort followed from 1989 to 2013.
The study sample consisted of 20,327 adults working at the French national electricity and gas company EDF-GDF. Annual exposure to PM10, PM10–2.5, PM2.5, NO2, O3, SO2, and benzene was assessed for the place of residence of participants using a chemistry-transport model and taking residential history into account. Hazard ratios were estimated using a Cox proportional-hazards regression model, adjusted for selected individual and contextual risk factors. Hazard ratios were computed for an interquartile range (IQR) increase in air pollutant concentrations.
The cohort recorded 1967 non-accidental deaths. Long-term exposures to baseline PM2.5, PM10-25, NO2 and benzene were associated with an increase in non-accidental mortality (Hazard Ratio, HR=1.09; 95% CI: 0.99, 1.20 per 5.9μg/m3, PM10-25; HR=1.09;
95% CI: 1.04, 1.15 per 2.2μg/m3, NO2: HR=1.14; 95% CI: 0.99, 1.31 per 19.3μg/m3 and benzene: HR=1.10; 95% CI: 1.00, 1.22 per 1.7μg/m3).The strongest association was found for PM10: HR=1.14; 95% CI: 1.05, 1.25 per 7.8μg/m3. PM10, PM10-25 and SO2 were associated with non-accidental mortality when using time varying exposure. No significant associations were observed between air pollution and cardiovascular and respiratory mortality.
Long-term exposure to fine particles, nitrogen dioxide, sulfur dioxide and benzene is associated with an increased risk of non-accidental mortality in France. Our results strengthen existing evidence that outdoor air pollution is a significant environmental risk factor for mortality. Due to the limited sample size and the nature of our study (occupational), further investigations are needed in France with a larger representative population sample.
•We assessed air quality using deterministic and geostatistical modeling approach.•We tested several lags of exposure including time-varying exposures.•We analyzed data of a large French cohort followed-up from 1989 to 2013.•Long-term exposure to several air pollutants was associated with all-cause mortality.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
From November 2018 through July 2019, an outbreak of Rift Valley fever in humans occurred in Mayotte, France; 142 cases were confirmed. Exposure to animals or their biological fluid was reported by ...73% of patients. Health authorities have been implementing control measures, including veterinary surveys, vector control interventions, and prevention measures.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Facemasks and respirators have been stockpiled during pandemic preparedness. However, data on their effectiveness for limiting transmission are scarce. We evaluated the effectiveness of facemask use ...by index cases for limiting influenza transmission by large droplets produced during coughing in households.
A cluster randomized intervention trial was conducted in France during the 2008-2009 influenza season. Households were recruited during a medical visit of a household member with a positive rapid influenza A test and symptoms lasting less than 48 hours. Households were randomized either to the mask or control group for 7 days. In the intervention arm, the index case had to wear a surgical mask from the medical visit and for a period of 5 days. The trial was initially intended to include 372 households but was prematurely interrupted after the inclusion of 105 households (306 contacts) following the advice of an independent steering committee. We used generalized estimating equations to test the association between the intervention and the proportion of household contacts who developed an influenza-like illness during the 7 days following the inclusion. Influenza-like illness was reported in 24/148 (16.2%) of the contacts in the intervention arm and in 25/158 (15.8%) of the contacts in the control arm and the difference between arms was 0.40% (95%CI: -10% to 11%, P = 1.00). We observed a good adherence to the intervention. In various sensitivity analyses, we did not identify any trend in the results suggesting effectiveness of facemasks.
This study should be interpreted with caution since the lack of statistical power prevents us to draw formal conclusion regarding effectiveness of facemasks in the context of a seasonal epidemic.
clinicaltrials.gov NCT00774774.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In Réunion Island, despite an influenza surveillance established since 1996 by the sentinel general practitioner's network, little is known about the etiology of Influenza like-illness (ILI) that ...differs from influenza viruses in a tropical area. We set up a retrospective study using nasal swabs collected by sentinel GPs from ILI patients in 2011 and 2012. A total of 250 swabs were randomly selected and analyzed by multiplex reverse transcriptase polymerase chain reaction (RT-PCR) including research of 18 viruses and 4 bacteria. We detected respiratory viruses in 169/222 (76.1%) samples, mostly rhinovirus (23.4%), influenza A virus (21.2%), influenza B virus (12.6%), coronavirus (4.9%) and Human metapneumovirus (3.6%). Nine swabs (5.3% of positive swabs) revealed co-infections with two viruses identified, among which six concerned co-infections with influenza viruses. We observed important seasonal differences, with circulation of Human Metapneumoviruses, RSV A and B and coronavirus only during summer; whereas parainfluenza viruses were identified only during winter. In conclusion, this study highlights a substantial circulation of multiple respiratory pathogens in Réunion Island throughout the year. It shows that ILI are not only attributable to influenza and underlines the need for biological surveillance. As the use of multiplex RT-PCR showed its efficacy, it is now used routinely in the surveillance of ILI.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
During the 2016-2017 austral summer, unprecedented water scarcity was observed in the south of Mayotte, French island in the Indian Ocean. Therefore, authorities introduced restrictive measures to ...save the water of this part of the island. The rationing system affected over 65,000 people, for four months. In order to detect a possible deterioration of the health situation, a strengthened epidemiological surveillance system was set up.
Surveillance focused on intestinal and skin diseases, which are often associated with a lack of hygiene or poor-quality drinking and bathing water. Three pathologies were monitored: acute diarrhoea, acute gastroenteritis and skin diseases and also, proportion of antidiarrhoeal and rehydration solutions sales in pharmacies. Cases of leptospirosis were also under surveillance. The analyses consisted of comparing the collected data according to the areas that were either affected or not affected by the water restrictions. Comparisons with historical data were also made.
Although none of the surveillance systems were able to demonstrate any impact on skin diseases, they revealed a very sharp increase in the proportion of consultations for acute diarrhoea and gastro-enteritis in the southern area. This was corroborated by a high increase in the sales of antidiarrhoeals and oral rehydration solutions via the sentinel pharmacists in the south of the island compared with those of the north. Comparison with historical data highlighted the occurrence of an unusual situation.
These water restrictions caused a real deterioration in the health status of the inhabitants who were deprived of water.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
During January-April 2015, a major outbreak of conjunctivitis on Réunion Island caused a large public health impact. On the basis of general practitioner consultations, emergency department visits, ...and eye medication sales during the 13-week epidemic, we estimated a total healthcare cost of €3,341,191 from the outbreak.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background: During August 2003, record high temperatures were observed across Europe, and France was the country most affected. During this period, elevated ozone concentrations were measured all ...over the country. Questions were raised concerning the contribution of O3to the health impact of the summer 2003 heat wave. Methods: We used a time-series design to analyze short-term effects of temperature and O3pollution on mortality. Counts of deaths were regressed on temperatures and O3levels, controlling for possible confounders: long-term trends, season, influenza outbreaks, day of the week, and bank holiday effects. For comparison with previous results of the nine cities, we calculated pooled excess risk using a random effect approach and an empirical Bayes approach. Findings: For the nine cities, the excess risk of death is significant (1.01%; 95% confidence interval, 0.58-1.44) for an increase of$10 \mu g/m^3$in O3level. For the 3-17 August 2003 period, the excess risk of deaths linked to O3and temperatures together ranged from 10.6% in Le Havre to 174.7% in Paris. When we compared the relative contributions of O3and temperature to this joint excess risk, the contribution of O3varied according to the city, ranging from 2.5% in Bordeaux to 85.3% in Toulouse. Interpretation: We observed heterogeneity among the nine cities not only for the joint effect of O3and temperatures, but also for the relative contribution of each factor. These results confirmed that in urban areas O3levels have a non-negligible impact in terms of public health.
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BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Rift Valley fever (RVF) is a vector-borne viral disease of major animal and public health importance. In 2018-19, it caused an epidemic in both livestock and human populations of the island of ...Mayotte. Using Bayesian modelling approaches, we assessed the spatio-temporal pattern of RVF virus (RVFV) infection in livestock and human populations across the island, and factors shaping it. First, we assessed if (i) livestock movements, (ii) spatial proximity from communes with infected animals, and (iii) livestock density were associated with the temporal sequence of RVFV introduction into Mayotte communes' livestock populations. Second, we assessed whether the rate of human infection was associated with (a) spatial proximity from and (b) livestock density of communes with infected animals. Our analyses showed that the temporal sequence of RVFV introduction into communes' livestock populations was associated with livestock movements and spatial proximity from communes with infected animals, with livestock movements being associated with the best model fit. Moreover, the pattern of human cases was associated with their spatial proximity from communes with infected animals, with the risk of human infection sharply increasing if livestock in the same or close communes were infected. This study highlights the importance of understanding livestock movement networks in informing the design of risk-based RVF surveillance programs.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Autochthonous malaria has been eliminated from Réunion in 1979. To prevent secondary transmission and re-emergence of autochthonous malaria, permanent epidemiologic and entomological surveillance and ...vector control measures are conducted around imported malaria cases. Results of local malaria surveillance (clinical data and results of epidemiological and entomological investigations around cases) were collected for 2013-2016 and were analysed according to historical data and to the exchanges with malaria-affected areas (estimated by airport data).
Form 2013 to 2016, 95 imported malaria cases have been detected in Reunion Island: 42% of cases occurred in the area of repartition of Anopheles arabiensis, but Anopheles mosquitoes were present only around seven cases including one gametocyte carrier. No autochthonous or introduced case has occurred during this period. The lack of chemoprophylaxis or poor adherence was found in the majority (96%) of malaria cases between 2013 and 2016, regardless of trip type. Affinity tourism in Madagascar and Comoros was the cause of 65% of imported malaria cases.
The incidence of imported malaria and the incidence rate per 100,000 travellers has continuously decreased since 2001. Now with the drastic decrease of malaria transmission in the Comoros archipelago, most of imported malaria cases in Reunion Island have been contaminated in Madagascar. Immigrants regularly resident in Reunion Island, which travel to malaria endemic countries (mainly Madagascar) to visit their friends and relatives (VFRs) represent a high-risk group of contracting malaria. VFRs, low adherence to pre-travel recommendations, in particular, the compliance on the use of chemoprophylaxis are the main drivers of imported malaria in Reunion Island. Furthermore as previously described, some general practitioners in Reunion Island are always not sufficiently aware of the official recommendations for prescriptions of prophylactic treatments.
Social mobilization targeted on the Malagasy community in Reunion Island could help to decrease the burden of imported malaria in Reunion Island. Because of the low number of gametocyte carriers and the absence of an Anopheles mosquito population when most malaria cases were imported those last 4 years, the risk of the appearance of introduced malaria cases and indigenous malaria cases appears low in Reunion Island.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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